Power coupling mechanism



Sept. 21, 1965 w. J. KOOY POWER COUPLING MECHANISM 2 Sheets-Sheet 1 Filed March 27, 1962 INVENTOR AYN% J. KOOY ATI'ORNEY Sept. 21, 1965 w. J. KOOY POWER COUPLING MECHANISM 2 Sheets-Sheet 2 Filed March 27, 1962 INVENTOR FOO nun

YNE J. KOOY BY 1 ATTO R N EY United States Patent 3,207,500 POWER COUPLING MECHANISM Wayne J. Kooy, Galien, Misha, assignor, by mesne assignments, to Heath Company, St. Joseph, Mich., a corporation of Delaware Filed Mar. 27, 1962, Ser. No. 182,889 2 Claims. (Cl, 26859) This invention relates to a coupling device which may be employed with a source of power to move an object such as, for example a door or other closure member, and is concerned primarily with the safety aspects of such an operating arrangement.

Movable building closure members such as doors, windows, and sliding panels pose a safety problem when power is used to actuate them. For example, if a person or animal is in a doorway when power is applied to move the door, great physical injury can easily result. In the event some inanimate object is in the path of operation of the door considerable damage can result both to the object and to the power mechanism which drives the door. For these reasons most power-operated door systems in use today have some type of safety device which includes means for sensing the presence of an object or obstruction in the doorway so that the movement of the door can be arrested. The sensing means associated with a poweroperated door usually controls the operation of the driving mechanism either to prevent or minimize damage. Most of the devices presently in use either interrupt the electrical power to the drive motor conventionally employed to operate the door, or alternatively, reverse the direction of the drive motor and thereby reverse the direction of movement of the door.

The type of safety device that merely interrupts the power from the drive motor does not ordinarily relieve the force present between the door and the object or obstruction if the sensing means is of the contact type. In fact with this type of arrangement, considerable additional damage to the object may result after power is removed from the motor due to the moving inertia of the power drive system.

In the type of safety device that reverses the motor, minimum harm or damage depends on the motor being reversed as quickly as possible and this arrangement obviously has its limitations since inertia is also a factor, although this factor is less important in this type than in that in which the power is removed from the motor. Both of these safety devices types are ordinarily constructed with components such as sensing devices, relays, etc., and therefore are disadvantageous in that they are relatively complicated and expensive and further, require servicing from time to time.

Accordingly, it is an object of this invention to provide a safety coupling mechanism for use with a poweroperated closure member in which the undesirable effect of inertia of the actuating system is substantially eliminated.

It is a further object of this invention to make available a safety device of the type described which is much simpler and less expensive than known devices for accomplishing the same purpose.

A still further object is to protect the drive mechanism of a power-operated door when a retarding force is encountered by the door which could damage the mechanism.

These and other objects, features and advantages of the invention will be best understood from a study of the following detailed description taken in conjunction with the claims and with the drawings in which:

FIGURE 1 shows a power-operated door arrangement utilizing a safety-coupling mechanism in accordance with the principles of my invention,

FIGURE 2 shows a perspective view of the safety couplin g mechanism employed in FIGURE 1,

FIGURE 3 is an enlarged view of the coupling mechanism shown in FIGURE 1 but with the springs and upper portions of the bolts removed for purposes of clarity,

FIGURE 4 shows the position of an operative release portion of the safety coupling mechanism under conditions of normal operation, and

FIGURE 5 shows the position of the operative release portion of FIGURE 4 under conditions of overload produced by a restraining force on the door due to an obstruction in the doorway.

Referring first to FIGURE 1, there is shown an arrangement for raising and lowering a door 10 of the overhead type; however, it will be understood that the principles of this invention may be employed with doors of various other types. The arrangement shown includes a power drive assembly 11 appropriately held by supporting members 12a and 12b. This assembly comprises a reversible electric motor 13 mounted on a suitable base 14 for driving a sprocket 15 on its shaft by means of a suitable speed reduction arrangement which includes the motor pulley 16, counter shaft pulley 17, and the belt 18. Electric motor 13 is connected to a electric power line by suitable electrical wiring (not shown) which includes a suitable switching arrangement (not shown) for starting, stopping and reversing the motor 13.

A track 19, preferably in the form of a metal bar having a T-shaped cross section, is suspended at one end by the base 14 and at its other end by a suitable bracket 20, which is secured, for example, to an upright 21 of a garage. An idler sprocket 22 is mounted at the opposite end of the track 19 from the driving sprocket 15 and a chain 23 engages both the sprockets 15 and 22. This chain forms a continuous closed loop around the T-bar upright section 19a and is connected at both of its ends to a safety device in the form of a trolley 24 for moving the trolley along the track 19. The door is mechanically connected to the trolley 24 by means of a suitable connecting arm 25 and pins or bolts 25a and 25b associated respectively with the door and the trolley.

Referring now particularly to FIGURES 2 and 3, the trolley 24 comprises generally two portions. The first portion includes a piece having a generally C-shaped crosssection 24a for embracing the flange 19b of the T-bar so that it will slide freely along the bar in a laterally constrained manner. Upright portions 26 are attached to this C-shaped portion to serve as a means for coupling the connecting arm 25 to the trolley through the pin or bolt 25b.

The second portion of the trolley 24 referred to above includes a piece having a generally U-shaped cross-section, the designation 2412 indicating the base of the U and the designation 240 indicating its sides thereof. The base 24b is provided with a slot 29 running longitudinally of the base and the track. A chain safety release member 30 is disposed in the slot 29 and is connected at its opposite ends to the ends of the chain 23. This chain release member 30 is made of a material having a thickness substantially less than the width of the slot 29 in which it is normally retained. The member 30 is further provided with a recessed or cut-out portion 31 having inclined cam surfaces 31a and 311) at each end thereof. The opposite ends 32a and 32b of the member 30 are connected to the ends of the chain 23. The member 30 is of a general zig-zag shape, see especially FIGURE 3, so that the cam portions 31a and 31b will cooperate with a pair of safety release members now to be described.

To one side of and above the slot 29 there is provided a trolley safety release member 33, pivotable at one end about a bolt 34 connected across the upright sides 24c.

A second trolley safety release member 35, similar in shape to that of the member 33 is provided above and to the other side of the slot 29 from the first member 33 and is pivotable about the bolt 36. Each of'the' pivotable members 33 and 35 is formed with substantially parallel sides with base portions 37 and 39 respectively. The base portion 24b by suitable holding pins 42a" and 43a to prevent axial movement of the bolt but to allow sidewise movement about the pins in the direction of the longitudinal axis of thetrolley 24. Helical compression loading springs 44 and 45 are provided over the bolts 42 and 43.

1 These springs are provided with nuts 46 and 47 to adjust the compressive forces of the springs 44 and 45 against spring support plates 48 and 49 respectively. These forces are in turn transmitted to the trolley safety release members 33 and 35 to maintain these members in a spring biased condition.

FIGURE 4 shows the chain safety release member 30 and the trolley safety release member 33 in their normal positions when the motor 13 is driving the chain 23 and I trolley 24 to the left to close the door 10.- The driving force from the chain 23 is transmitted through the trolley 24 to the door 10 by means of the cam surface 31a on the member and the inclined lip cam follower surface -on the member 33. Specifically, when the chain 23 is moved in the direction of the door the cam surface 31a on the member 30 will be urged against the cam follower or lip 40 on the pivotable member 33. Since the member 33 is held down by the compressive force of the spring 44, it will be forced to travel in the direction of the movement of the chain. The member 33 is held to the trolley frame by the bolt 34 and the trolley will therefore move to the left along the track, thus closing the door 10.

In the event the door meets an obstruction as it is being closed, a retarding force will be transmitted through the connecting arm 25 to the trolley 24. This will result in a greater-than-normal force between the cam surface 31a of the member 30 and the cam follower surface 40 of the member 33. This will urge the member 33 pivotally upward about the bolt 34, against the force of the spring 44 to the position shown in FIGURE 5. The chain safety release member 30 therefore becomes disengaged or decoupled from the member 33, allowing it to move freely with the chain 23. The chain 23 will continue to move a result of the retarding force on the trolley due to door friction. It will also be clear that the compressive force of the spring 44 must not be so great that the cam and 'follower surfaces 31a and 40 will disengage only after the door has exerted a damaging force on the obstruction. The ideal value of spring pressure will of course vary depending upon the particular door system for which the device is used.

When an obstruction has caused the chain safety release member 30 to travel out of its normal position in the slot 29, it is returned to the normal position merely by reversing the direction of the motor 13. In the case just considered the member 30 will therefore be moved to the right in FIGURE 5 by the pull of the chain until it reaches the position where the cam surface 31a re-engages the lip 40. At this point the member 33 will have re- 4 turned from its position shown in FIGURE 5 to that shown in FIGURE 4. The door can then be closed by again reversing the motor after the obstruction has been removed.

FIGURES 4 and 5 illustrate the manner of operation of the safety device when the door is being closed and for purpose of clarity, only the trolley release member 33 and its associated components have been shown therein. It will be appreciated from the foregoing, however, that when the chain 23 is moving to the right in order to open the door 10 that a similar disengaging or decoupling action is achieved should the door meet a' binding force during the opening operation. Assuming such a binding force, the cam surface 31b on the member 30 will, by reason of the greater force produced on the cam follower 41, urge the member 35 against the compressive spring force of the spring 45 to a position such as that shown by the member 33 in FIGURE 5. This will of course allow the member 30 to travel freely to the right with the chain 23, thereby preventing a damaging load be .particular pressure required will depend upon the weight of the door, the friction of the door moving system and other factors such as the use of springs which are frequently used to partially counteract the weight of the door.

There are a number of important advantages to the safety coupling mechanism described herein. One of these is that it is far simpler than known safety devices conventionally employed with power operated doors since an elaborate system for sensing an object in the doorway and for removing or reversing the power from the motor is unnecessary. It is consequently, also less expensive. Another advantage is that the driving mechanism is decoupled from the door when an obstruction is encountered. As a result, the potential for producing damage is not as great as in systems where the power is merely removed from the driving motor since in such systems the moving inertia of the drive mechanism tends to increase any damage produced on the obstruction. Additionally, the safety mechanism described herein eliminates the possibility of damage to the mechanical and electrical components of the drive system. Still another advantage of this device is that it decouples the driving system not only when an obstruction is in the doorway, but also in the event that a binding force is encountered between the trolley and the track. The typical prior art safety device merely interrupts operation action only in the event there is an obstruction in the doorway.

The invention has been described with particular reference to a power-operated door of the overhead type, however, it will be obvious that this devicemay be employed with various types of doors, as well as with windows and movable building closure panels generally. Additionally,

the principles taught herein can be utilized in still other applications, such as for example factory conveyor systems where it would be advantageous to decouple the drive mechanism from the over-all moving system in the event a restraining force is encountered.

Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not a limiting sense.

I claim:

1. A mechanical safety arrangement for transmitting mechanical driving power from a power source to a movable door comprising:

a guide and a trolley movable on said guide,

means for mechanically connecting said door to said trolley for movement therewith,

said trolley including a drive safety release member movable relative to the trolley and having first and second cam surfaces and connected to said power source, a pair of driven safety release members individually connected to the trolley, and a pair of springs individually associated with different ones of said driven members for urging them into coupled engagement with different ones of the cam surfaces of said drive member for transmitting driving power to said door when said door is allowed to move freely,

said first cam surface transmitting power through one of said driven members to move said door in one direction and said second cam surface transmitting power through the other driven member to move said door in a direction opposite to said one direction,

each of said springs exerting between the driven member with which it is associated and its cam surface a force having a magnitude which will allow said drive member to be decoupled from one or the other of said driven members when said door encounters excessive restsraining force as it is moved in one direction or the other.

their pivot points adjacent opposite longitudinal extremities of the slot and individually having a cam follower surface adapted for movement into engagement with a different one of the first and second cam surfaces,

and a pair of springs mounted on said trolley and individually associated with different ones of said driven members for pivotally urging their cam follower surfaces into engagement with the corresponding ones of the drive member cam surfaces for transmitting driving power from said source to said trolley when said door is allowed to freely move,

said first cam surface transmitting power through one or the other of said driven members when said door encounters excessive restraining force as it is moved in one direction or the other.

2. A mechanical safety arrangement for transmitting mechanical driving power from a power source to a movable door comprising:

a track and a trolley movable along said track,

a mechanical linkage for connecting a door to said trolley for movement therewith,

said trolley including a doubly-bent drive safety release References Cited by the Examiner UNITED STATES PATENTS member movably disposed in a slot in said trolley 2,695,781 11/54 W longitudinal of said track and connected to said power 219 5 6,5 14 10/60 BIShOP 104 128 source and having a first cam surface located on one 3,043,237 7/62 McKee et a1 104128 side of the slot and a second cam surface located on 3,091,191 5/63 Fur 104-172 the other side of the slot, a pair of driven safety release members individually pivotally connected to the 3 trolley in a side-by-side manner above said slot with 5 HARRISON R. MOSELY, Primary Examiner. 

1. A MECHANISM SAFETY ARRANGEMENT FOR TRANSMITTING MECHANICAL DRIVING POWER FROM A POWER SOURCE TO A MOVABLE DOOR COMPRISING: A GUIDE AND A TROLLEY MOVABLE ON SAID GUIDE, MEANS FOR MECHANICALLY CONNECTING SAID DOOR TO SAID TROLLEY FOR MOVEMENT THEREWITH, SAID TROLLEY INCLUDING A DRIVE SAFETY RELEASE MEMBER MOVABLE RELATIVE TO THE TROLLEY AND HAVING FIRST AND SECOND CAM SURFACES AND CONNECTED TO SAID POWER SOURCE, A PAIR OF DRIVEN SAFETY RELEASE MEMBERS INDIVIDUALLY CONNECTED TO THE TROLLEY, AND A PAIR OF SPRINGS INDIVIDUALLY ASSOCIATED WITH DIFFERENT ONES OF SAID DRIVEN MEMBERS FOR URGING THEM INTO COUPLED ENGAGEMENT WITH DIFFERENT ONES OF T HE CAM SURFACES OF SAID DRIVE MEMBER FOR TRANSMITTING DRIVING POWER TO SAID DOOR WHEN SAID DOOR IS ALLOWED TO MOVE FREELY, SAID FIRST CAM SURFACE TRANSMITTING POWER THROUGH ONE OF SAID DRIVEN MEMBERS TO MOVE SAID DOOR IN ONE DIRECTION AND SAID SECOND CAM SURFACE TRANSMITTING POWER THROUGH THE OTHER DRIVEN MEMBER TO MOVE SAID DOOR IN A DIRECTION OPPOSITE TO SAID ONE DIRECTION, EACH OF SAID SPRINGS EXERTING BETWEEN THE DRIVEN MEMBER WITH WHICH IT IS ASSOCIATED AND ITS CAM SURFACE A FORCE HAVING A MAGNITUDE WHICH WILL ALLOW SAID DRIVE MEMBER TO BE DECOUPLED FROM ONE OR THE OTHER OF SAID DRIVEN MEMBERS WHEN SAID DOOR ENCOUNTERS EXCESSIVE RESTRAINING FORCE AS IT IS MOVED IN ONE DIRECTION OR THE OTHER. 